Apparatus for forming and dimpling bends in tubing



April 29. 1958 F. .1. FucHs, JR., r-:rAL 2,832,393

APPARATUS FOR FORMING AND DIMPLING BENDS IN TUBING Filed March 1 1954 2 Sheets-Sheet 1 ma T R. M E E m w u v H E LW m w M wllkn. I] 4 F. H O O O ....II. J L. il lulllbw l. mv m2 5f, v E ma m if-- o o Y mmm Q N A Ov n o I l A W \\J.\ r NN Nn M m mv 1-.. mwvmmw o o fwn. m o 1U. w m .x o Q O\ mm mfo. OBW nw o vw r. rlv Vv MM Aq w wm E Q um .Ill

2,832,393 APPARATUS FOR FORMING- AND DIMPLING BENDS 1N TUBING Filed March 1, 1954 Aprilv 29, `1958 F. J. FucHs, JR., ETAL 2 Sheets-Sheet 2 BY GMC..

APPARATUS FOR FRMING AND DIMILING BENDS 1N TUBING Francis J. Fuchs, Jr., and Howard L. Haneline, Winston- Salem, N. C., assignors to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application March 1, 1954, Serial No. 413,404

4 Claims. (Cl. 153-2) This invention relates broadly to die forming of ma terials and more specifically to apparatus for forming and dimpling angular sections of rectangular tubing.

ln certain uses of relatively thin-walled rectangular tub ing, for example as electrical wave guide elements, it is necessary to elfect angular bends in the tubing and to tions of rectangular wave guide tube comprises first sub-` jecting a straight section of tube to a rough bending process as exemplified by the method and apparatus disclosed in coapending application of Francis J. Fuchs, lr., Serial No. 412,730, filed February 2'5, 1954, wherein a rst wail of the tube is subjected to an angular or approximately zero radius bend and a second opposite wall of the tube assumes the form of a smooth curve.

A second step then comprises placing the roughly bent tube from the first step into a die forming apparatus and operating upon the tube to produce therein the final desired angular configuration and any desired deformations of accurately controlled shape and location.

It is an objectof the present invention to provide a die forming and dimpling apparatus for performing the operation of the above second step.

` In Order to attain this and other objects, a preferred embodiment of the present invention includes a base, a plurality of stationary die sections secured to the base and forming a generally angular' die cavity for the reception therein of a tube to be formed and dimpled. An angur lar forming die is slidably mounted on the base and adapted to produce in one wall of the tube a sharp angular configuration. A convex dimplingdie is slidably mounted upon the base and adapted, upon actuation, to engage another wall of the tube to produce a `concavo-convex dimple .4

in the other wall. A slide block is slidably mounted on the base and serves to support a mandrel which is slidabiy insertable into the tube and bears upon one extremity thereof i a pivoted arcuate cam for supporting and forming the interior of the one wall of the tube opposite the angular forming die. The one extremity of the mandrel is also provided with a grooved inclined surface having slidably mounted thereon a slidable forming section which is plo vided with a plane surface and a concavity for supporting and forming the other wall of the tubing. A ram is reciprocably mounted on the base and is slidably keyed to a cam block which is slidably engageable with the slide block and adapted to actuate the convex dimpling die substantially simultaneously with the actuation of the pivoted arcuate cam.

Other novel features and advantages of theinvention 'will become apparent upon reference to the following de- States Patent O 2,832,393 Patented Apr. 29, 1958 ICE scription when considered in conjunction with the following drawings, wherein: i

Fig. 1 is a top plan view, partly in cross section, of the forming and dimpling apparatus showing the mandrel in a retracted position;

Fig. 2 is a view similar to Fig. 1 showing the mandrel in position inside the tube prior to the forming and dimpiing operation;

Fig. 3 is a fragmental top plan View of the forming and dimpling apparatus after actuation thereof;

Fig. 4 is a fragmental top plan View, partly in cross section, showing a formed and dimpled tube, one extremity of the mandrel in an actuated position therein and the slidable forming section in position for retraction of the mandrel;

Fig. 5 is a cross-sectional view taken `on line 5-5 of Fig. 3;

Fig. 6 is a perspective view of a tube before the forming and dimpling thereof;

Fig. 7 is a perspective view `of a tube after the forming and dimpling thereof; and

Fig. 8 is an enlarged fragmental cross-sectional view taken on line 8 8 of Fig. 1.

Referring now to the drawings and more particularly to Fig. 1, the numeral 12 designates a base .having rigidly secured thereto a plurality of upright guide and support members 13, 141,` 16 and 17'. The upright supporting member 1'/ is spaced from the upright supporting member 16 and has, on the extremity thereof adjacent the member 16, an angularly disposed surface 2t?, thereby defining with the member 16 an angular space d5'. Stationary die sections 18, 19, 21, 22 and 2T.- are rigidly secured to the base by suitable means and denne a generally rectangular die cavity 24 for the reception therein of a tube 26 to be formed and dimpled.

The top of the tube 26 as illustrated in Figs. l-4 has been removed in order to give a clearer understanding of the configurations and interrelationships of the working parts of the apparatus.

A convex dimpling die 27 is slidably mounted upon the base 12 between the stationary die sections 19 and 21. IThe dimpling die 27 is provided at one extremity thereof with an arcuate convex surface 2.3 and at the other extremity thereof with a plane inclined surface 29.

An angular forming die 3l is slidably mounted upon the base 12 between the stationary die sections 22 and 23 and is provided at one extremity thereof adjacent the die cavity 24 with plane faces 32 intersecting in a sharp angle and adapted for engagement with one wall of the tube Z6 to be formed. A wedge-member 33 is slid-ably mounted upon the base 12 between the upright supporting member 13 and the stationary die section 23 and is provided at one extremity thereof with an inclined surface 34 for engagement with the forming die 31.

A slide bloclr. designated generally by the numeral 36 is slidably mounted upon the base 12 between the upright supporting members 1d and 16 and consists of a body 37 and a collar 3d detachabiy secured to one extremity of the body 37. The body 37 is provided at one extremity thereof with a cylindrical cavity 39' and with a passage ill extending longitudinally through the body 37 and interconnecting with the cylindrical cavity 39. The

passage d1 is provided near one extremity thereof with a restricted portion thereby forming an annular seat 50. The body 37 is also provided with an aperture 42 extending longitudinally of the body 37 and interconnecting with the cylindrical cavity 39. The body 37 is further provided at the other extremity thereof with an inclined plane surface 43. A passageway 40 extends longitudi nally through the slide block consisting of the assembled body 37 and collar 38. The collar 38 is provided on one surface thereof with a projecting arm 44- engageable with the wedge member 33. The collar 3S is also provided with a circular aperture 46 having a diameter slightly less than the diameter of the cylindrical cavity 39 whereby when the collar 38 is secured to the body 37 the-collar 38 forms annular shoulder 47 adjacent the cylindrical cavity 39.

A mandrel designated generally by the numeral 4S includes a rigid stem 55 which is slidably insertable into the tube 26 and has an enlarged extremity mounted in the cylindrical "cavity 39. The mandrel stem cxtends forwardly of the body 37 through the circular aperture 46 of the collar 38. The length of the enlarged extremity 49 of the stem 55 is slightly less than the length of the cylindrical cavity 39 thereby permitting a limited sliding movement or fioat of the mandrel 4S through the distance d relative to the slide block 36. The stem 55 is provided with an aperture 66 extending longitudinally therethrough and alignable with the aperture 42 in 'the body 37. The stem 5S is also provided, near the Iother extremity thereof, with an arcuate cavity 51 and `with a slot S2 extending through the stern 55 and interconnecting with the arcuate cavity 51. An arcuate cam 53 is rotatably mounted in the arcuate -cavity S1 and is connected to the mandrel stem 55 by means of a pivot pin 54. The arcuate cam 5.3 is provided with a plane surface 65 for engagement with a portion of the one `wall of the tube 26 opposite the forming die 31. The stem 55 is also provided with a longitudinally extending passage 56 interconnecting with the slot 52 and alignable with the passage 41 in the body 37. The other or free extremity of the stem 55 is also provided with an inclined plane surface 57 having a groove SS extending the length thereof. A slidable forming section 59 is provided on one side thereof with a projecting tongue 61 for engagement with the groove 5S and with a concave depression 62 alignable with the passage 66 in the stern 55. The other side of the slidable forming die is provided with a plane surface 63 and a concavity 64. When the slidable section 59 is mounted on the stem 55 and the mandrel is in operating lposition within the tube 26, the concavity 64 is opposed to the convex surfact 2S of the dimpling die 27.

A locking pin 67 is secured by suitable means in the aperture 42 in the body 37, extends through the aperture 66 in the stem S5, and when the rearward or righthand extremity of the stern 55 abuts the right-hand lwall of the cavity 39, the left-hand extremity of the pin 67 projects beyond the stem 55 for a distance substantially equal to the oating distance d into the concave depression 62 to lock the `slidable forming section 59 in a forming position on the stem 55.

A cam block 68 is slidably mounted upon the base 12 between upright supporting members 14 and 17 and is provided on one extremity thereof with a first inclined plane surface 69 for engagement with the inclined plane surface 43 on the slide block 36 and on the other extremity thereof with a projecting key 75 (Fig. 8) and with a second inclined plane surface 71 engageable with the angularly disposed surface 2.0 on the upright supporting member 17. The cam block 68 is also provided with a longitudinally extending passage 72 longitudinally ali-gnable with the passage 41 in the body 37, the passage 72 having a diameter substantially greater than the larger diameter of the passage 41.

A ram 73 is slidably mounted upon the base ft2 between the upright supporting members 14 and 17 and is provided at one extremity thereof with a key slot titi for slidable engagement with the cam blocl; 63. The other extremity of the ram 73 is adapted for connection, by means of a shaft 74, to a power operated reciprocating means i( not shown).

A cam rod 76 is secured at one extremity thereof to the ram 73 and extends through the passages 72, 41 and 56-in the cam block 68, the body 37 and the stem 55,

able section 59 in position on the mandrel.

ously with the forward movement of the cam rod 76 respectively. The rod 76 is provided with an enlarged portion 70 for abutment with the annular seat 50 of the passage 4l in the slide blocl; 36. An angular cam 77 is secured to the other extremity of the cam rod 76 and is slidably mounted in the slot 52 for camming engagement with the arcuate cam An actuating bar 78 is slidably mounted in the passageway 40 in the slide block 36 and has a forward portion thereof in slidable engagement with the upright guiding and supp "ting member i6 and the stationary die sections and 2l. The forward or left-hand extremity of the actuating bar 7S (Fig. l) is provided with an inclined plane surface 79 engageable with the plane surface 29 on the dimpling die 27.

The stationary die section 18 and the upright supporting members f3, i4, 16 and 17 are provided with threaded apertures Si whereby retaining plates (not shown) may be detachably secured to the forming and dimpling apparatus for securing the working parts of the apparatus in their functional relationships and for supporting a top wall of the tube during. the forming and dimpling thereof.

In operation, the tube 26 to be formed and dimpled (Fig. 6) is positioned in the angular die cavity 24 with the mandrel 48 in the retracted or unactuated position (Fig. l). lf desired, a retaining plate (not shown) may be clamped in position above the tube by bolting such plate to the stationary die section 18 and the upright supporting member 13 by means of the threaded apertures 81. The ram 73 is then actuated by the shaft 74 whereby the cam block 68 and the slide block 36 are moved linearly to the left (Fig. l) to feed the mandrel 48 into the rearward or right-hand extremity of the tube Z6 (Fig. l) to the position shown in Fig. 2. In this position the rearward or right-hand extremity of the mandrel 4S is in Contact with the rearward or right-hand wall of the cylindrical cavity 39 in which position the locking pin 67 projects forwardly from the mandrel 48 into the depression 62 to lock the slidable section 59 in position. When the slide block 36 reaches the position shown in Fig. 2, the arm 44 contacts the wedge member 33 whereby the inclined surface 34 of the 'wedge member 33 engages the forming die 31 to force the forming die 31 into engagement with the one wall of the tube 26. `In this position (Fig. 2), additional forward movement of the slide block 36 is prevented and the second inclined plane surface 71 of the cam block 68 is adjacent the angularly disposed plane surface 20 of the upright supporting member 17. Continued forward movement of the ram 73 results in `an angular movement of the cam block 68 into the angular space 45 thereby allowing `the cam rod 76 and the attached angular cam 77 to move to the left relative to the mandrel 48 whereby the cam 77 engages and rotates the arcuate cam S3 in the arcuate cavity 51 into engagement with a portion of the interior of the one wall opposite to the forming die 31 thereby sharpening the angular configuration in the one wall (Fig. 3).

During the forward movement of the slide block 36 and the attached mandrel 48, the rearward or right-hand extremity of the mandrel 48 is in contact with the reari ward or right-hand wall of the cylindrical cavity 39, in which position the locking pin 67 projects forwardly of the mandrel 48 into the depression 62 to lock the slid- Simultaneand the actuation of the arcuate cam 53, the angular movement of the cam block 68 into the angular space 45 results in an engagement of the cam block 68 with the rearward or right-hand extremity of the actuating bar 78, thereby moving the actuating bar 73 forwardly or to the left so that the inclined plane surface 79 on the forward extremity of the actuating bar 78 contacts the plane inclined surface 29 on the dimpling die 27 whereby the convex surface 28 on the dimpling die 27 engages the other wall of the tube 26 opposite the concavity 64 on the oneness te nl? slidable section 59 to produce a concavo-convex deformation or dimple in the other wall of the tube. The stationary die sections 19 and El cooperate with the plane surface 63 on the opposed slidable section 59, and with the stem 55, respectively, to produce an angular conguration in the other wall of the tube 26. p

Upon completion of the dimpling and forming operations, the retaining plate (if one has been used) is removed and the ram 73 moved to the right thereby moving the attached cam rod 76 to the right until the enlarged portion 70 of the cam rod 76 abuts the annular seat El) of the passage 41 in the slide block 36 to move the slide block 36 to the right. The mandrel 43 is held by friction Within the tube 26 while the slide block 36 moves to the right through the distance d thereby retracting the locking pin 67 from the depression 62 to unlock the slidable section 59. Continued movement to the right of the slide block 36 results in the abutment of the forward or left-hand portion of the enlarged extremity 4K9 of the mandrel 43 with the annular shoulder 47 of the collar 38 to move the mandrel 48 also to the right. rl`he slidable section 59 is thereby moved in the groove 58 (Figf4) to clear the dimple in the other wall of the tube 26 thereby allowing retraction of the mandrel 48 without distortion of the dimple. The rearward movement of the slide block 36 also releases the arm 4dfrom engagement with the wedge 33 to unlock the forming die 31 and the continued rearward movement of the cam block 6d releases the actuating bar '78 from engagement with the dimpling die 27. The forming die 31 and the dimpling die 27 may then be retracted from engagement with the tube 26 and the formed and dimpled tube (Fig. 7) removed from the apparatus.

It is to be understood that the above described elements are simply illustrative of the application and principles of the invention and that numerous other arrangements may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.

What is claimed is:

l. An apparatus for simultaneously forming and dimpling angular bends in rectangular tubes comprising a base, a plurality of stationary die sections secured to said base and dening an angular die cavity for the reception therein of a tube, aconvex dimpling die slidably mounted on said base adjacent said die cavity, an angular forming die slidably mounted on said base adjacent said die cavity and opposite said dimpling die, a wedge member slidably mounted on said base and engageable with said forming die, a slide block slidably mounted on said base and having an inclined plane surface on one extremity thereof and an arm extending from the other extremity thereof and engageable with said wedge member, said slide block also having a cavity adjacent one extremity thereof and lirst and second passages extending longitudinally of said slide block and interconnecting with said cavity, said rst passage having an annular seat therein, a rigid mandrel stem mounted at one extremity thereof in said cavity and slidably movable therein for a limited distance, said stem having first and second passages extending longitudinally thereof, said first passage in said stem being alignable with said iirst passage in said slide block, said stem being provided at the other extremity thereof with a grooved inclined surface and adjacent said other extremity with an arcuate cavity and a longitudinally extending slot interconnecting with said arcuate cavity, an arcuate cam pivoted to said stem and rotatably mounted in said arcuate cavity, a forming section slidably mounted on said grooved inclined surface and having on one surface thereof a plane forming surface and a concavity for opposing said dimpling die and on the other surface thereof` a depression aligna'ole With said second passage in said stern, a locking pin secured to said slide block and extending through said second passage in said stem and into said depression to lock said` forming section to said stem, a cam block slidably mounted on said base and engageable with said inclined surface on said slide block, said cam block having therein a passage longitudinally alignable with said rst passage in said slide block and having a diameter substantially larger than the diameter of said first passage in said slide block, a ram reciprocably mounted on said base and slidably keyed to said cam block, a cam rod secured at one extremity thereof to said ram and extending through the passage in said cam block and through said iirst passages in said slide block and said stem, said cam rod being provided with an enlarged portion for engagement with said annular seat in said first passage in said slide block, an angular cam slidably mounted in said slot in said stem, said angular cam being secured to another extremity of said cam rod and engageable with said arcuate cam, an actuating bar slidably mounted in a third passage in said slide block, and engageable with said dimpling die, means to move said ram forwardly whereby said mandrel stem is inserted into said tube, said forming die is engaged with one wall of said tube, said forming section is loclted in position on said stem, said arcuate cam is pivoted into engagement with said one wall opposite said forming die to angularly form said one wall, said cam block is engaged with said actuating bar to force said dimpling die into engagement with another wall of said tube opposite said concavity on said forming section thereby producing a concavo-convex dimple in said other wall, and means to move said ram rearwardly whereby said enlarged portion of said cam rod engages said annular seat in said rst passage in said slide block to move said slide block rearwardly relative to said mandrel stem to retract said locking pin from said depression thereby releasing said forming section for slidable movement on said stern whereby said mandrel stern may be withdrawn from said tube without distorting said dimple in said other wall.

2. Apparatus for forming and dirnpling tubes comprising a base, means to securely position a tube on said base, an angular forming die slidably mounted on said base and engageable with one Wall of said tube, a diinpling die slidably mounted on said base and engageable with another wall of said tube, a mandrel reciprocably mounted on said base and slidably insertable in said tube, one extremity of said mandrel being provided with a rotatable arcuate cam for opposing said forming die and with a slidable section having a concavity on one surface thereof for opposing said dimpling die, means to reciprocate said mandrel, means to lock said slidable section in position during the forming and dimpling operation and to unlock said slidable section upon completion of said forming and dimpling operation, and means to rotate said arcuate cam to angularly form said one wall and to simultaneously actuate said dtunpling die to dimple said other wall.

3. Apparatus for forming and dimpling tubes comprising a base, means to securely position a tube on said base, a forming die slidably mounted on said base, a dimpling die slidably mounted on said base, a mandrel reciprocably mounted on said base and having on one extremity thereof a pivoted cam and a concavity, and means to reciprocate said mandrel including means to cause said forming die to iirst engage one wall of said tube and then to urge said cam and said dimpling die 'to simultaneous actuation to form and dimple said tube.

4. A tube forming apparatus comprising a base, a pl-.irality of stationary die sections secured to said base for positioning a tube on said base and for supporting portions of the external walls of said tube, an angular forming die slidably mounted on said base and engageable with one wall of said tube, a mandrel reciprocably mounted on said base and slidably insertable into said tube, said mandrel having on one extremity thereof a rotatable cam for engaging said one wall opposite said lsf: v References Cited in the le of this patent UNITED STATES PATENTS Dallmeyer Dec. 30, 1919 Caneld Feb. 15, 1921 Grotnes Aug. 1, 1933 Crabtree Dec. 10, 1940 Greene Aug. 18, 1950 FOREIGN PATENTS Norway June 7, 1915 

